X-linked Juvenile Retinoschisis via the RS1 Gene
Summary and Pricing 
Test Method
Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes| Test Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
|---|---|---|---|---|---|
| 7807 | RS1 | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
Testing run on PG-select capture probes includes CNV analysis for the gene(s) on the panel but does not permit the optional add on of exome-wide CNV analysis. Any of the NGS platforms allow reflex to other clinically relevant genes, up to whole exome or whole genome sequencing depending upon the base platform selected for the initial test.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
This test is also offered via a custom panel (click here) on our exome or genome backbone which permits the optional add on of exome-wide CNV or genome-wide SV analysis.
Turnaround Time
3 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Clinical Features
X-linked Juvenile retinoschisis (XLRS, OMIM 312700) is a relatively common early onset vitreo-retinal degeneration disorder which affects 1 in 5,000-25,000 young males. XLRS is characterized by mild to severe loss in visual acuity, splitting (schisis) of inner retinal layers in the peripheral retina, and a reduction in the b-wave of the electroretinogram (ERG) (George et al. Br J Ophthalmol 79(7):697–702, 1995; Bowles et al. Invest Ophthalmol Vis Sci 52(12):9250-9256, 2011; Sieving et al. GeneReview, 2009). Secondary complications include retinal detachment, vitreous hemorrhage and neovascular glaucoma, which may lead to impaired vision or blindness (George et al., 1995; Li et al. Mol Vis 13:804-812, 2007). The hallmark of XLRS is the occurrence of a “spoke-wheel” pattern in the macula of young patients due to the development of tiny cysts in the retina (Molday et al. Prog Retin Eye Res 31(3):195-212, 2012).
Genetics
RS1 (MIM 300839), which is located on Xp22.1, is the only gene that is mutated in XLRS affected males. RS1 encodes a 224 amino acid (aa) protein called retinoschisin, which is secreted from retinal cells and binds to the surface of photoreceptors and bipolar cells to help maintain the structural and functional integrity of the retina (Molday et al., 2012). XLRS is inherited in an X-linked recessive manner; females are usually asymptomatic and rarely have associated peripheral retinal changes. XLRS is reported to exhibit complete penetrance in males with variable expressivity (Sieving et al., 2009). The RS1 gene comprises six exons, which encode a 23 aa N-terminal leader or signal sequence (exons 1-2), a 39 aa retinoschisin domain (exon 3), a highly conserved 157 aa discoidin domain and a 5 aa C-terminal segment (exons 4–6) (Bowles et al., 2011; Molday et al., 2012). Mutation analysis reveals a high preponderance of causative missense mutations in the discoidin domain, which may affect XLRS1-specific protein-protein interactions and suggest its biological significance. There are over 200 causative mutations in RS1 that have been reported and XLRS seems to be mainly caused by loss-of-function mutations only, rather than an abnormal function from the mutant protein (The Retinoschisis Consortium 1998; The Human Gene Mutation Database).
Clinical Sensitivity - Sequencing with CNV PG-Select
RS1 mutations are identified by sequence analysis in 90–95% of males with a clinical diagnosis of XLRS (Sieving et al. Trans Am Ophthalmol Soc 97:451-464, 1999; Sikkink et al. J Med Genet 44(4):225-232, 2007)
Testing Strategy
This test provides full coverage of all coding exons of the RS1 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.
Indications for Test
Candidates for this test are patients with symptoms consistent with X-linked Juvenile retinoschisis, family members of patients who have known mutations and carrier testing for at-risk family members.
Candidates for this test are patients with symptoms consistent with X-linked Juvenile retinoschisis, family members of patients who have known mutations and carrier testing for at-risk family members.
Gene
| Official Gene Symbol | OMIM ID |
|---|---|
| RS1 | 300839 |
| Inheritance | Abbreviation |
|---|---|
| Autosomal Dominant | AD |
| Autosomal Recessive | AR |
| X-Linked | XL |
| Mitochondrial | MT |
Disease
| Name | Inheritance | OMIM ID |
|---|---|---|
| Retinoschisis 1, X-Linked, Juvenile | XL | 312700 |
Related Test
| Name |
|---|
| Flecked Retina Disorder Panel |
Citations
- Bowles, K. et al. (2011). "X-linked retinoschisis: RS1 mutation severity and age affect the ERG phenotype in a cohort of 68 affected male subjects." Invest Ophthalmol Vis Sci 52(12):9250-9256. PubMed ID: 22039241
- George, N.D. et al. (1995). "X linked retinoschisis." Br J Ophthalmol 79(7):697–702. PubMed ID: 7662639
- Human Gene Mutation Database (Bio-base).
- Li, X. et al. (2007). "Clinical features of X linked juvenile retinoschisis in Chinese families associated with novel mutations in the RS1 gene." Mol Vis 13:804-812. PubMed ID: 17615541
- Molday, R.S. et al. (2012). "X-linked juvenile retinoschisis: clinical diagnosis, genetic analysis, and molecular mechanisms." Prog Retin Eye Res 31(3):195-212. PubMed ID: 22245536
- Sieving, P.A. et al. (1999). "Juvenile retinoschisis: a model for molecular diagnostic testing of X-linked ophthalmic disease." Trans Am Ophthalmol Soc 97:451-464; discussion 464-9. PubMed ID: 10703138
- Sieving, P.A. et al. (2009). "X-Linked Juvenile Retinoschisis." GeneReviews. PubMed ID: 20301401
- Sikkink, S.K. et al. (2007). "X-linked retinoschisis: an update." J Med Genet 44(4):225-232. PubMed ID: 17172462
- The Retinoschisis Consortium. (1998). "Functional implications of the spectrum of mutations found in 234 cases with X-linked juvenile retinoschisis." Hum Mol Genet 7(7):1185-1192. PubMed ID: 9618178
Ordering/Specimens
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.
Specimen Types
Specimen Requirements and Shipping Details
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ORDER OPTIONS
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